In file-based collaboration systems, it is common to allow sharing of files via “invitation links” to grant access to files and folders. Such systems may allow one user to send a link (e.g., in the form of a URL) to another user over e-mail, social networking websites, or any other communication medium. The other user may view or modify the contents of the file or folder by clicking on the link. The invitation links can be generated by a plug-in or processed running at a web-browser or an email application (e.g., Outlook®). For example, a user can select one or more attachments, and a link to the attachments is generated and sent by email.
The links are often sent to a group of users who are the intended recipients. The link or invitation is typically not coded to uniquely designate the recipients. Therefore, the link (embedded in an email) can be mistakenly forwarded to an un-intended recipient or forwarded by an authorized user to an unauthorized user. In addition, a hacker who duplicitously gained access to emails containing such links can easily download and view documents pointed to by the link. Furthermore, it is difficult or impossible to distinguish such malicious use of the invitation from legitimate use by the intended recipient.
Therefore, although it is easy and convenient to share documents via links or invitations, such solutions are often not sufficiently secure and can be easily compromised. Furthermore, such solutions do not ensure that documents pointed to by a shared link are not accessed by unauthorized users.
Some existing solutions attempt to provide a security layer to such links or emails. One solution is based on authentication that either requires the recipient to register a user account in the system or to previously own such an account. This is not always a desirable requirement for “ad-hoc” collaboration. It is often desirable to invite external users to a corporate system in which they do not have an account. Furthermore, it may be prohibitive or otherwise inconvenient for the recipient to go through the complex process of registering a new user account, dealing with the overhead of remembering another password, and so on.
It would therefore be advantageous to provide a solution for securely providing email attachments that would overcome the deficiencies noted above.